Pressure demand exhalation valve



United States Patent Inventor Galen M. Glidden South Haven, MichiganAppl. No. 715,270

Filed March 22, 1968 Patented Aug. 18, 1970 Assignee Automatic SprinklerCorporation of America Cleveland, Ohio PRESSURE DEMAND EXHALATION VALVE6 Claims, 2 Drawing Figs.

U.S. Cl 137/102 Int. Cl A62b 9/02, I F16k 15/14 Field of Search 137/102,63r

[56] References Cited UNITED STATES PATENTS 2,954,793 10/1960 Seeler137/102 3,232,304 2/1966 Koester 137/102 Primary Examiner- William F.ODea Assistant Examiner- William H. Wright AttorneyChristel and BeanABSTRACT: A pneumatic tire element cooperates with a flapper valve diskby engaging the disk along an annular line of contact displaced inwardlyof but close to the marginal edge of the disk which engages the valveseat. The marginal edge of the disk thus is positively located withrespect to the valve seat but is free to flex out of contact with it.

Patented Aug. 18, 1970 FIG. I

INVENTORY GALEN M.'GL|DDEN %/%o ATTORNEYS PRESSURE DEMAND EXl-IALATIONVALVE BACKGROUND OF THE INVENTION This invention relates generally tobreathing fluid control art, and more particularly to a new and usefulpressure demand exhalation valve assembly.

Protective face masks designed to provide an external source ofbreathing atmosphere for the wearer conventionally employ an inhalationvalve providing access to the external source of breathing atmosphereand an exhalation valve permitting the users breath to be expelledexternally. It is of interest particularly in conjunction with theexhalation valve to provide a positive closing action while at the sametime eliminating the necessity for an undesirably greater differentialin pressure to actuate the valve.

BRIEF SUMMARY OF THE INVENTION The present invention is directed to animproved form of exhalation valve assembly for use in conjunction withprotective masks and the like as explained hereinabove wherein theexhalation valve consists of a flapper type element and a tire elementwhich is subjected internally to the pressure of and is in communicationwith the external source of breathing atmosphere, the tire elementhaving a marginal lip cooperative circumferentially with the flappervalve element for effecting uniform control thereover.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING FIG. I is a sectionalview taken through an inhalation-exhalation valve embodying theexhalation valve assembly according to the present invention;

FIG. 2 is a sectional view taken through the tire element of theexhalation valve assembly.

DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 1, arespirator valve assembly is indicated generally therein by thereference character 10, it being appreciated that the valve assembly isadapted to be fitted to a face mask 12 or similar entity for dispositionof the mouthpiece portion 14 in close proximity to the users mouth. Themouthpiece portion 14 is provided with a central opening I6 throughwhich the user breathes in externally supplied oxygen or air, and alsowith an outlet opening 18 through which the expelled breath may pass asdisclosed more particularly hereinafter. The mouthpiece may be aseparate element, as shown, fitted to the main body 20 of the valveassembly. Body portion 20 is provided with an inlet tube 22 which may beexternally threaded as at 24 for connection to the female portion of aflexible conduit, not shown, leading to a source of breatheableatmosphere. The inner end of inlet 22 carries a mounting web 26 whichaffixes the stem 28 of an inhalation flapper valve assembly 30 to theinlet tube. The flapper valve 30 is provided with a marginal edgeportion 32 normally bearing against the annular face 34 of the inlettube and adapted to perform a one-way valving action to permit theinduction of the breatheable atmosphere. An exhalation flapper valveassembly indicated generally by the reference character 36 is providedand consists of a flapper valve element 38 and a tire element 40.Flapper valve element 38 is provided with an annular collar portion 42embracing the inlet tube 22, as shown. Element 38 also includes a flatdisk-like portion 44 projecting radially from the collar 42 and whichmerges with an arcuate annular lip portion 46 which terminates in aradial edge portion 48 laterally offset from the portion 44 and adaptedto seat against the annular surface 50 of body 20, thereby normallyclosing an outlet passage 52' leading to the aforementioned exhalationpassage 18.

Since protective devices such as these frequently find application intoxic environments it is practical and important to assure effective andcomplete closing of the exhalation valve, thereby to prevent back flowof the toxic atmosphere into the interior of the mask. At the same time,it is undesirable to so increase the pressure differential necessary toopen the exhalation valve as to cause discomfort to the user.Accordingly, the particular shape of the flapper valve 38 describedabove acting in conjunction with the tire element 40 forms a cooperativecombination of elements which serves to eliminate the possibility ofback flow of the external atmosphere and minimizes the pressuredifferential necessary to operate the valve and expel the internalatmosphere therethrough.

To this end, tire element 40 is provided with a pair of mounting collarportions 54 and 56 which are joined by a specially configurated wallelement forming the space 58 which, through openings 60in the collar 56,registering with openings 62 in the inlet tube 22 via an annular groove61 therearound communicates with the source of external breatheableatmosphere. This normally provides a slightly positive pressure in thespace 58 relative to the ambient external atmosphere. Collar 56 acts asa spacing collar between walls 64 and 68, and both collars can bemounted by split rings 63, as shown.

The wall joining the two collars 54 and 56 includes a generally radialportion 64 projecting from collar 54 and joining a generallycircumferential portion 66 which extends beyond another generally radialwall portion 68 joined to collar 56 and then turns back under in anarcuate portion 70 to form the annular nose 72.

The dimension of tire element 40 is such as to place nose 72 inengagement with the arcuate lip portion 46 of flapper valve element 38in slightly inwardly spaced relationship to the free marginal edge 74 ofthe radial edge portion 48. This assures complete peripheral contact ofmarginal edge portion 48 against annular face 50 to provide a positivesealing action preventing the inadvertent back flow of the ambientatmosphere into the interior of the protective device. I

At the same time, it allows the relatively flexible marginal edge 48 ofthe flapper valve 38 to deflect readily and at relatively low pressuredifferential existing across such flapper valve, thereby minimizing theeffort on the part of the user. It will be appreciated of course thatthe tire element itself may deflect slightly and the combined flexure oftire element 40 and the resiliency of flapper valve element 38 combinein minimizing the effort involved in opening the exhalation valve whileat the same time assuring the positive sealing action specified.

The action of tire 40 on flapper valve 38 is unidirectional, andmovement of tire element 40 away from flapper valve 38 for any reasonwill not in itself open the latter. Valve 38 is designed to beself-closing, and if tire 40 should collapse somewhat under aninspiration-demand effort made by the user, the pressure differentialacross valve 38 would hold it closed. Further, the design of tire 40 andvalve 38 is such that they would cooperate to hold valve 38 closed evenupon some collapsing of tire 40. If that should occur, it is believedthat nose 72 would move across lip 46 and thereby continue to exert aclosing action on valve 38.

lclaim:

1. A respirator valve assembly comprising, in combination:

a tubular inlet member adapted for connection to an external source ofbreatheable atmosphere,

one-way valve means for controlling flow of breatheabl atmospherethrough said inlet member,

an annular exhalation valve seat around said inlet member and providinga valve opening therewith for flow of expelled breath to ambientatmosphere,

and an exhalation valve assembly normally closing said valve opening,said valve assembly comprising an annular disk extending radially fromsiad inlet member to overlie said annular valve seat, a tire memberembracing said inlet member and projecting radially therefrom, said tirehaving a marginal portion in generally axial alignment with said valveseat and hearing against said annular disk adjacent the peripherythereof, and means communicating the interior of said tire with theinterior of said inlet member upstream of said one-way valve means 2.The assembly as defined in Claim 1, wherein said disk includes anannular main body portion, an annular radial edge portion laterallyoffset from said main body portion and normally bearing flatwise againstsaid annular valve seat, and an arcuate annular lip portion joining saidmain body and radial edge portions, said marginal portion of the tirebearing against the flapper valve disk being in the form of a laterallyoffset annular nose, said nose engaging said lip portion of said diskadjacent said radial edge portion.

3. The assembly as set forth in Claim 1, wherein said tire includes apair of generally radial wall portions each having a mounting collarengaging said inlet member, one of said collars spacing apart said wallportions, and means providing a communicating passage through said onecollar and said inlet member.

4. The assembly as set forth in Claim 2, wherein said tire includes afirst generally radial wall portion joined to a circumferential portionextending toward said valve seat and beyond another generally radialwall portion, said circumferential portion turning back to said otherradial wall portion to form said nose.

5. The assembly as set forth in Claim 4, wherein one of said generallyradial wall portions extends from a mounting collar engaging said inletmember and spacing apart said radial wall portions.

6. A respirator valve assembly comprising, in combination: a tubularinlet member adapted for connection to an external source of breatheableatmosphere, one-way valve means for controlling flow of breatheableatmosphere through said inlet member, an annular exhalation valve seataround said inlet member and providing a valve opening therewith forflow of expelled breath to ambient atmosphere, and an exhalation valveassembly normally closing said valve opening, said valve assemblycomprising an annular disk extending radially from said inlet member tooverlie said annular valve seat, a tire member embracing said inletmember and projecting radially therefrom, said tire having a marginalportion bearing against said annular disk adjacent the peripherythereof, and means communicating the interior of said tire with theinterior of said inlet member upstream of said one-way valve means, saidtire includes a pair of generally radial wall portions each having amounting collar engaging said inlet member, one of said collars spacingapart said wall portions, and means providing a communicating passagethrough said one collar and said inlet member.

